We only use these values in vertex conversion. We can instead pass more
info to the convertGPU/CPU functions. In client attribute streaming
we can query the format table a second time. This is a bit slower. But
the runtime of attribute streaming would usually be dominated by the
conversion function time. So it shouldn't regress any real work perf.

This saves on a bit of storage and memory overhead in the vertex sync
functions in VertexArrayVk.

Bug: angleproject:3014
Change-Id: I401eeff024664aa0efeea710503c0f619e6d4f22
Reviewed-on: https://chromium-review.googlesource.com/c/1406889
Commit-Queue: Jamie Madill <jmadill@chromium.org>
Reviewed-by: Yuly Novikov <ynovikov@chromium.org>